The exemplary embodiments relate to a screen and a projector, and in particular to a transmission screen that is suitable for rear projectors.
Screens, in particular, screens to project projected light from a projector are roughly classified into one of a reflection screen and a transmission screen. The reflection screen reflects projected light and scatters (diffuses) the light in directions of observers. The reflection screen is mainly used for front-type projectors. The transmission screen transmits projected light and scatters the light in directions of observers. The transmission screen is mainly used for rear projectors.
In any one of the screens, it is possible to concentrate the scattered light in, for example, a normal direction of the screen by setting a scattering angle (a diffusion angle) of the projected light to a predetermined value. Consequently, observers in front of the screen can observe a bright projected image.
In order to guide light projected on the screens in a predetermined direction, screens with structures using a lenticular lens and a micro-lens array have been proposed (see, for example, JP-A-2001-305315 and JP-A-2003-29344).
In the screen with the structure using a lenticular lens, projected light is condensed by the lenticular lens, for example, in a horizontal direction of the screen viewed from observers. In this case, the projected light is not condensed in a vertical direction orthogonal to the horizontal direction. In the screen with this structure, there is a problem in that an angular field of view, that is, a range in which a projected image can be observed is extremely narrow in the vertical direction compared with the horizontal direction.
In the screen with the structure using a micro-lens array, a plurality of micro-lens elements are arranged in an array. The respective micro-lens elements refract projected light concentrically in a normal direction of the screen with an optical axis as a center. Many of the observers are often present in the horizontal direction with respect to the screen. On the other hand, the observers are rarely present in the vertical direction of the screen. Therefore, in the screen including the micro-lens array of the related art, projected light is refracted and guided in unnecessary directions in which observers are not present. As a result, in the screen including a micro-lens array, it is difficult to guide projected light effectively only in directions in which observers are present. Thus, there is a problem in that a projected image is dark.